Answer:
6000
Step-by-step explanation:
first you do 40000-28000 =12000 that means we have 12000 left
12000÷2 because the shirt equals 2 to give 6000
Answer:
what's the question??
Step-by-step explanation:
( yx + 4x - 5 )( y + 1 )
.....................................
Answer:
You can proceed as follows:
Step-by-step explanation:
Suppose that the matrix 
is invertible, and suppose that at least one of the matrices 
is not invertible. Without loss of generality suppose that the matrix 
is not invertible. Remember the important result that a matrix is invertible if and only if its determinant is nonzero. Then,
On the other hand, the determinant of a products of matrices is the product of the determinants of the matrices, that is to say,
But we supposed that is not invertible. Then 
. Then 
. This contradicts the fact that
and then the three matrices 
must be invertible matrices.
